The present invention relates to a securing device for scanner, more particularly to a securing device, which can automatically secure the scanning means of an image scanner.
FIG. 1 shows the schematic diagram of a conventional scanner with a securing device. The scanner 60 has an image scanning means 70 driven by a motor module 80, which is powered by an external DC power source. The scanner further comprises a securing device 90 with a securing hole 95. As shown in FIG. 2, the securing hole 95 secures the image scanning means 70 to restrict the movement of the image scanning means 70 when the scanner is not used. When the scanner is to be used, the securing hole 95 is operated manually to unlock the image scanning means 70 whereby the image scanning means 70 can be moved by the motor module 80 for scanning operation.
(1) Since the securing hole is operated manually to unlock the image scanning means, the user may directly operate the scanner without unlocking the image scanning means due to careless mistake. Therefore, the motor will be idled, and possibly damaged due to overheating.
(2) The position of the image scanning means may be deviated because the user does not correctly operate the securing device.
(3) The position of the image scanning means may be deviated due to machancial clearance.
It is an object of the invention to provide an easily used securing device, which is operated automatically, rather than manually, to secure or unlock the image scanning means of the scanner.
It is another object of the invention to provide a securing device for scanner, which is operated to secure or unlock the image scanning means of the scanner to prevent the problem of position deviation and motor idling.
To achieve above object, the present invention provides a securing device for scanner comprising a scanner main body and a relay means. The scanner main body houses an image scanning means driven by a motor unit, the motor unit connected to a driving circuit. The relay means is connected between the driving circuit and an external DC power source for supplying electrical power to the image scanning means. The relay means comprises an electromagnetic coil and two switches. The electromagnetic coil is connected to the DC power source fed through an insertion hole on the scanner main body. The two switches are electrically connected to the driving circuit. The securing device automatically locks the image scanning means when the DC power source does not send electrical power to the relay means.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: